Purpose: Gene Delivery Module Research aimed at understanding the development, physiology, and pathology ofthe visual system has been aided enormously by the advent of technologies for exogenously expressing foreign genes and inhibiting expression of endogenous genes. Over the past 5 years, the Gene Delivery Module (GDM) has played an important role in helping Berkeley Vision Science researchers employ these technologies, and has fostered collaborations among visual system labs. The Module two facilities in Barker and Minor Hall that have designed, prepared, and purified gene constructs specifically for somatic cell gene transfer to ocular tissues. It has also helped investigators create germline animal models of basic ocular processes and ocular disease.